HOLT, Mich. -- A Michigan elementary school was placed on temporary lockdown Tuesday when a second grade student brought a grenade into the building for show-and-tell, the Detroit Free Press reported.

After learning there was a US military grenade in the building, Steve Netzel, principal at the Elliott Elementary School in Holt, Mich. -- about 80 miles (125km) west of Detroit -- immediately called local authorities.

When the Michigan State Police bomb squad arrived on the scene, they declared the possible World War II-era device as inactive, according to the Ingham County Sheriff's Department.

"We had the Michigan State Police bomb squad come out and retrieve the device for us," Sgt. Robert Ott, Ingham County Emergency Manager, said in a press conference.

"For safety reasons, you gotta know what they're doing. They shouldn't have access to weapons of any type of anything that looks like a weapon."

There were no pending charges and no reported injuries, according to officials.